1. Field of the Invention
The present invention relates to a liquid crystal display device, and particularly to a technique that is effectively applied to an in-cell liquid crystal display device having a built-in touch panel.
2. Description of the Related Art
There are display devices having a device (hereinafter also referred to as a touch sensor or a touch panel) that inputs information by performing a touch operation (contact pressure operation, and hereinafter simply referred to as touch) on a display screen with a user's finger, a pen, or the like. The display devices are used in mobile electronics such as PDAs and portable terminals, various kinds of home appliances, automated teller machines, and the like.
As such a touch panel, an electrostatic capacitance type touch panel detecting a change in the capacitance of the touched portion is known.
Well known as the electrostatic capacitance type touch panel is a so-called in-cell liquid crystal display device of which a liquid crystal display panel has a touch panel function as disclosed in JP2009-258182A.
In the in-cell touch panel, the counter electrode (also referred to as a common electrode (CT)), which is formed on a first substrate (also referred to as a TFT substrate) constituting the liquid crystal display panel, is divided, and is also used to serve as scanning electrodes of the touch panel.